Thank you James & everybody for your sound advice. Yes. I am using Cloudflare CDN. I think i configured it properly. And i had a look to my web using Webpagetest.org. But there is a lot of data. I think i need a professional help later on.
Thank you Tara. I already noted your instructions. And i will follow them later on. I think it will be very helpful to others like me out there, too. If there is any problem later on, i will be back to the forum.